The present invention, a solar concentrator cross-section design, consists of a concave reflective boundary and of a first receiver-converter (a term intended to embrace conversion to forms of energy such as heat and electricity) extending from the base of the concavity outward toward the aperture of the reflective boundary and of at least a second receiver-converter following outward after said first toward said aperture wherein said second receiver-converter is well removed from said first and the multiple receiver-converters may communicate with each other. The considerable removal of said second receiver-converter from said first is as far as at least partly within the major portion of the distance from said base to said aperture up to as far as said aperture and at least as far as one and one-half times the distance from said base at the point from which extension of said first receiver-converter begins to the termination of said first receiver-converter nearest said aperture. Said removal is important to reducing interference by said second receiver-converter with reception of radiation on said first on which high concentration ratio is desired. The considerable extent of such interference reduction is not realized without analytical examination.
The object of the present invention is to provide a solar collector embracing an excellent combination of capacity, concentration ratio and efficiency which is appropriate and economical for space and water heating and feed chemical preheating.
The present invention would serve well as the cross-sectional design of an end-to-end tilted, linear trough for heating of a liquid in the two receiver-converters which would run lengthwise in the trough and transport the liquid, the first receiver-converter (in the base of the trough) is the hot tube and the second is the "cold" tube. Placement of both hot and "cold" tubes in the trough more nearly assures (by placing both tubes in the same environment) that both tubes will achieve equal temperatures with minimum delay during an extended absence of sunlight. Such is important because the embodiment is intended to depend on passive, natural circulation (no pumps, no valves, no draining of tubes at night) from a reservoir, down the "cold" tube and back up the hot tube and then to the reservoir, as a result of the liquid in the hot tube being less dense, thus lighter, than that in the "cold" tube. In a prolonged absence of sunlight, it is important that both tubes attain the same temperature readily to avoid circulation and cooling of reservoir contents. Both tubes enter said reservoir from essentially the same level.